Conventional machine arrangements for bottle and can manufacturing are typically linear and are generally referred to as machine lines. That is, the machine lines, with each and every processing and/or forming machine, extend in a single line. The articles are passed through the machine line only once to achieve a desired stage of manufacture. Such a “single-pass” arrangement may take up a large amount of space in a warehouse, factory, or other location. Occasionally, buildings are not large enough or long enough to house such complex and long machine arrangements. For example, in bottle or can operations, many different types of processes need to be performed on the bottle or can, such as necking, curling, expansion, trimming, etc. Each type of process may also require a plurality of machines to sufficiently perform the overall process. For instance, necking operations may require multiple operations with multiple machines in order to properly neck a bottle or can of a certain length or size. A downside of the conventional single-pass arrangement is that the machine lines may need to include duplicate or additional machines to perform the desired function(s), increasing both the cost and footprint of these machines.
Machine arrangements have been developed that perform a single recirculation of cans or bottles. Such arrangements extract cans or bottles from a downstream point after they have passed through the machine line once and transport the cans or bottles to an upstream point for reloading the machine to effect a second pass through the machine line. That is, each processing or forming machine in the machine line within the recirculation loop receives cans or bottles at two different stages of manufacturing. On the first pass through the machine line, each machine performs a first operation on the cans or bottles. These operations result in cans or bottles at a single stage of manufacture. These cans or bottles are then recirculated for a second pass through the machine line. On the second pass, each machine performs a second operation on the can or bottle, resulting in a can or bottle at the desired stage of manufacture. The can or bottle is then passed to subsequent downstream single pass machine operations then output from the machine line for further processing. These machine arrangements achieve the same number of required process stages with as little as half the number of line starwheels versus a single-pass counterpart. This results in a generally lower-cost machine with a generally smaller footprint, but sacrifices throughput of the machine. In such a two-pass system, the cans or bottles received by the recirculation loop are always at the same stage of manufacture.
Such two-pass systems are non-synchronous, as they do not require pocket correlation in that only a single-stage container is involved. The non-synchronous nature of such a system prevents performance of more than one recirculation because the cans or bottles may be placed in the wrong position for recirculation. Such improper placement results in collisions, jams, non-uniform products being delivered downstream from the system, combinations thereof, or the like.
Two pass recirculation typically employs vacuum belt technology for extracting the container from a starwheel (e.g., a necker), while typically employing legacy gravity infeed track technology for re-introduction of the container into the necker. Random accumulative conveyance has been used for transport between extraction and re-introduction. The implementation of a multi-pass recirculation loop with more than two passes requires that discrete pocket correlation be maintained during the entire recirculation loop. Random accumulation during transport does not provide necessary pocket correlation.
Thus, development of a discrete container transport system presents the need for new container handling equipment and hardware.